Teaching aid for ultrasound wave theory



FIG. 1 is a front perspective view of a teaching aid for ultrasound wave theory showing my new design;

FIG. 2 is a front elevational view;

FIG. 3 is a rear elevational view; and,

FIG. 4 is a side elevational view, the opposite side being a mirror image thereof. 

The ornamental design for a teaching aid for ultrasound wave theory, as shown and described. 